GIA Diamond Cut Grading Update
May 03, 04
During the annual GIA Gemfest at the BaselWorld Fair, the gem laboratory provided an overview of their ongoing study in Diamond Cut Research. The research, which has been in progress for several years, will ultimately result in a comprehensive diamond cut grading system.
According to GIA's CEO Tom Yonelunas, the cut of a diamond can be determined by the stone's brightness, fire and scintillation.
When examining the stone's scintillation, GIA observers took into account not only the gem's 'sparkle' (the light reflected from the stone's facets) but also pattern-related effects.
Pattern related scintillation is caused by the dark and light areas within the stone (dark upper girdle, fish eye center, etc). The final assessment of the stone also takes into account the diamond's 'overall art quality' and level of craftsmanship
To date, the GIA has carried out some 70,000 observations in more than 2,000 stones during their grading system research.
The new system will pilot towards the end of 2004, with the GIA also intending to incorporate the extended cut quality information on all GIA reports and diamond dossiers for standard round, D-Z diamonds.